Search results for "Resistance"
showing 10 items of 3641 documents
Betulinic Acid Kills Colon Cancer Stem Cells
2016
Cancer stem cells (CSCs) are considered to be the origin of cancer and it is suggested that they are resistant to chemotherapy. Current therapies fail to eradicate CSCs and therefore selecting a resistant cell subset that is able to facilitate tumor recurrences. Betulinic acid (BetA) is a broad acting natural compound, shown to induce cell death via the inhibition of the stearoyl-CoA- desaturase (SCD- 1). This enzyme converts saturated fatty acids into unsaturated fatty acids and is over-expressed in tumor cells. Here we show that BetA induces rapid cell death in all colon CSCs tested and is able to affect the CSCs directly as shown, via the loss of clonogenic capacity. Similar results were…
A naturally occuring triterpene saponin ardisiacrispin B displayed cytotoxic effects in multi-factorial drug resistant cancer cells via ferroptotic a…
2018
WOS: 000432722700010
Cytotoxicity of a naturally occuring spirostanol saponin, progenin III, towards a broad range of cancer cell lines by induction of apoptosis, autopha…
2020
Abstract This study was aimed to investigate the cytotoxic potential of a natural compound, progenin III on a broad range of cancer cell lines, including various sensitive and drug-resistant phenotypes. The cytotoxicity, progenin III-induced autophagic, ferroptotic and necroptotic cell death were evaluated by the resazurin reduction assay (RRA). Spectrophotometric analysis of caspases activity was performed using caspase-Glo assay. Flow cytometry was applied for cell cycle analysis (PI staining), apoptosis (annexin V/PI staining), mitochondrial membrane potential (MMP) (JC-1) and reactive oxygen species (ROS) (H2DCFH-DA). Progenin III and the reference molecule, doxorubicin exerted cytotoxi…
Cytotoxicity of epunctanone and four other phytochemicals isolated from the medicinal plants Garcinia epunctata and Ptycholobium contortum towards mu…
2018
Abstract Introduction Resistance of cancer cells is a serious impediment to chemotherapy and several phytochemicals are active against multi-drug resistant (MDR) phenotypes. The cytotoxicity of five naturally occurring compounds: betulin (1), mundulea lactone (2), seputhecarpan A (3), seputheisoflavone (4) and epunctanone (5) was evaluated on a panel of 9 cancer cell lines including various sensitive and drug-resistant cell lines. The modes of action of compound 5 were further investigated. Methods The resazurin reduction assay was used to evaluate cytotoxicity of samples and ferroptotic cell death induced by compound 5; caspase-Glo assay was used to detect the activation of caspases in CCR…
SERCA and P-glycoprotein inhibition and ATP depletion are necessary for celastrol-induced autophagic cell death and collateral sensitivity in multidr…
2019
Multidrug resistance (MDR) represents an obstacle in anti-cancer therapy. MDR is caused by multiple mechanisms, involving ATP-binding cassette (ABC) transporters such as P-glycoprotein (P-gp), which reduces intracellular drug levels to sub-therapeutic concentrations. Therefore, sensitizing agents retaining effectiveness against apoptosis- or drug-resistant cancers are desired for the treatment of MDR cancers. The sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) pump is an emerging target to overcome MDR, because of its continuous expression and because the calcium transport function is crucial to the survival of tumor cells. Previous studies showed that SERCA inhibitors exhibit anti-c…
Analysis of cross-resistance to Vip3 proteins in eight insect colonies, from four insect species, selected for resistance to Bacillus thuringiensis i…
2018
Abstract Bacillus thuringiensis Vip3 proteins are synthesized and secreted during the vegetative growth phase. They are activated by gut proteases, recognize and bind to midgut receptors, form pores and lyse cells. We tested the susceptibility to Vip3Aa and Vip3Ca of Cry1A-, Cry2A-, Dipel- and Vip3-resistant insect colonies from different species to determine whether resistance to other insecticidal proteins confers cross-resistance to Vip3 proteins. As expected, the colonies resistant to Cry1A proteins, Dipel (Helicoverpa armigera, Trichoplusia ni, Ostrinia furnacalis and Plodia interpunctella) or Cry2Ab (H. armigera and T. ni) were not cross-resistant to Vip3 proteins. In contrast, H. arm…
Fungicide resistance towards fludioxonil conferred by overexpression of the phosphatase gene Mo PTP 2 in Magnaporthe oryzae
2018
The fungicide fludioxonil causes hyperactivation of the Hog1p MAPK within the high-osmolarity glycerol signaling pathway essential for osmoregulation in pathogenic fungi. The molecular regulation of MoHog1p phosphorylation is not completely understood in pathogenic fungi. Thus, we identified and characterized the putative MoHog1p-interacting phosphatase gene MoPTP2 in the filamentous rice pathogen Magnaporthe oryzae. We found overexpression of MoPTP2 conferred fludioxonil resistance in M. oryzae, whereas the 'loss of function' mutant ΔMoptp2 was more susceptible toward the fungicide. Additionally, quantitative phosphoproteome profiling of MoHog1p phosphorylation revealed lower phosphorylati…
Multi-omics approaches to improve malaria therapy.
2021
Malaria contributes to the most widespread infectious diseases worldwide. Even though current drugs are commercially available, the ever-increasing drug resistance problem by malaria parasites poses new challenges in malaria therapy. Hence, searching for efficient therapeutic strategies is of high priority in malaria control. In recent years, multi-omics technologies have been extensively applied to provide a more holistic view of functional principles and dynamics of biological mechanisms. We briefly review multi-omics technologies and focus on recent malaria progress conducted with the help of various omics methods. Then, we present up-to-date advances for multi-omics approaches in malari…
Cancer stem cell-based models of colorectal cancer reveal molecular determinants of therapy resistance
2016
Abstract Colorectal cancer (CRC) therapy mainly relies on the use of conventional chemotherapeutic drugs combined, in a subset of patients, with epidermal growth factor receptor [EGFR]-targeting agents. Although CRC is considered a prototype of a cancer stem cell (CSC)-driven tumor, the effects of both conventional and targeted therapies on the CSC compartment are largely unknown. We have optimized a protocol for colorectal CSC isolation that allowed us to obtain CSC-enriched cultures from primary tumor specimens, with high efficiency. CSC isolation was followed by in vitro and in vivo validation, genetic characterization, and drug sensitivity analysis, thus generating panels of CSC lines w…
Elucidating the molecular physiology of lantibiotic NAI-107 production in Microbispora ATCC-PTA-5024.
2016
Background The filamentous actinomycete Microbispora ATCC-PTA-5024 produces the lantibiotic NAI-107, which is an antibiotic peptide effective against multidrug-resistant Gram-positive bacteria. In actinomycetes, antibiotic production is often associated with a physiological differentiation program controlled by a complex regulatory and metabolic network that may be elucidated by the integration of genomic, proteomic and bioinformatic tools. Accordingly, an extensive evaluation of the proteomic changes associated with NAI-107 production was performed on Microbispora ATCC-PTA-5024 by combining two-dimensional difference in gel electrophoresis, mass spectrometry and gene ontology approaches. R…